Multi-trolley container crane with bi-level track switching capability

ABSTRACT

The invention relates to a multiple trolley container crane having at least two trolley tracks ( 6, 7 ) disposed one on top of the other, on which trolleys ( 8 ) having running wheels, drive devices, and lifting devices move. Characterized in that
         running wheels ( 20 ) that can be laterally retracted and extended, and   an integrated lifting system ( 21, 22, 24, 25, 26 ) are disposed on the trolleys ( 8 ) on the trolley tracks ( 6, 7 ), with which they support themselves on or next to the trolley tracks ( 6, 7 ) and thereby get from the lower to the upper trolley tracks ( 6, 7 ) and vice versa.       

     The invention is suitable for fast loading and unloading of container ships, where several containers are supposed to be loaded and unloaded from them at the same time (Figure).

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of German Application No.103 13 769.6 filed on Mar. 22, 2003 Applicant also claims priority under35 U.S.C. §365 of PCT/DE2004/000583 filed on Mar. 22, 2004. Theinternational application under POT article 21(2) was not published inEnglish.

The invention relates to a multiple trolley container crane having atleast two trolley tracks disposed one above the other, in accordancewith the preamble of the first claim.

The invention is suitable for cranes in which several trolleys aredisposed on different trolley tracks, whereby there is the possibilitythat the trolleys switch from one trolley track to another. The systemis particularly suitable when the possibility is supposed to exist thatseveral trolleys switch their tracks at the same time, moveindependently of one another, and no specific location is required forchanging the trolleys from one trolley track to the other. The inventioncan be used in very particularly advantageous manner when severaltrolleys pick up containers at the same time and, traveling one behindthe other, bring the containers to the planned location. This can takeplace both from a container ship to a vehicle that is standing ready, orto a collection area, and vice versa.

Since container ships are becoming larger and larger, and because of thedocking times in the harbors, there is a demand for loading andunloading as many containers as possible within the shortest possibleamount of time, and at a high speed. It is true that several containerbridges can be placed next to one another against the container shipsalong the longitudinal side of the ship, but these are predominantlysingle-trolley container bridges, i.e. one trolley picks up thecontainer from the ship and brings it to the pier, or vice versa. In thecase of large container ships, this means long docking times.

A container crane having two trolleys is known from DE 298 24 751.8,which trolleys can work independently of one another. The proposedvariant is limited to two trolleys, however, so that several containercranes must be used for fast unloading.

A load loading crane is known from DE 43 07 254 A 1, in which threetrolleys are disposed on a container bridge, whereby two lifting unitsthat can be moved in their longitudinal direction, having a liftingmechanism and a transfer unit are disposed for the load exchange. In thecase of this system, the advantage of the transport path division iscanceled out by the multiple release and gripping of the container.

A transport system is known from EP 0 167 235 A 1, with which severalcontainers, one after the other, can be loaded onto and unloaded from aship, but the trolleys always move on the same tracks, so that whileseveral trolleys can load and unload containers at the same time, thesystem has the disadvantage that first, all of the loading and unloadingprocedures must have been completed, before the next unloading andunloading procedures can be carried out.

In order to move several trolleys on different tracks at the same time,without these hindering one another, a portal crane having circulatingtrolleys is known from WO 00/48 937, in which several trolleys aredisposed next to and on top of one another, and move on different tracksin two different level heights. A disadvantage of this portal cranehaving circulating trolleys, however, is that the upper trolleys withthe hoists only perform the lifting and lowering movements of thecontainers, and the trolleys on the lower tracks only take over thetransport of the containers to and from. It is true that severalcontainers can be lifted and transported at the same time, but differenttrolleys are required for the transport and for lifting, which trolleyshandle the lifting and transport procedure with a division of labor. Asa result, a multiple transfer of containers on the container crane isrequired, and this results in an increased use of materials and errorsources. Furthermore, in the case of two or more lifting and loweringtrolleys, there are significant crossover problems between the liftingand transport procedure. It is also disadvantageous that every containermust be brought into the uppermost trolley lifting position in order tobe transferred and transported further. It is furthermoredisadvantageous that a switch in track is always possible only at theend of the tracks, so that significant distances must be traveled by thetrolleys.

It is therefore the task of the invention to develop a multiple trolleycontainer crane on which several trolleys can move at the same time, atdifferent height levels, whereby the transport of several containers issupposed to be possible with a simple method of construction andprocedure.

This task is accomplished by means of a multiple trolley container cranethat has the characteristics of the first claim.

Dependent claims reproduce advantageous embodiments of the invention.

The solution according to the invention provides for a multiple trolleycontainer crane having at least two trolley tracks disposed one on topof the other, on which trolleys having running wheels, drive devices,and lifting devices move, which crane is characterized in that thetrolleys on the trolley tracks have running wheels that can be laterallyretracted and extended. These running wheels are retracted during theswitch of the trolley from one trolley track to the next higher trolleytrack, and are extended again on the next higher trolley track.Fundamentally, at least two trolley tracks disposed on top of oneanother must be disposed on each side of the trolley. It is alsopossible to dispose more than two trolley tracks one on top of theother. Every trolley has an integrated lifting system with which it cansupport itself on or next to the trolley tracks and thereby get from onetrolley track to the other trolley track. In this connection, it ispossible that the trolley moves from an upper trolley track to the onelocated below it. The lifting system can not only engage on a trolleytrack, i.e. in front of or behind the running wheels, it can also engageon a suitable location next to a trolley track. After the lifting systemis supported on or next to the trolley track, the lifting systemtransports the running trolley, with the wheel pairs retracted, up ordown, and afterwards, the wheel pairs are extended again, after thelifting movement, and the trolley is lowered to the running surface.Afterwards, the lifting system can be retracted again.

When only two trolley tracks are present, the track width of the runningwheels can be adjusted by means of fixed stops.

Telescoping cylinders that are disposed next to or under each runningwheel are suitable as an integrated lifting system.

However, gear wheels that are used to move racks are also suitable; theybring about an upward or downward slide of the trolley, in eachinstance.

Every trolley is provided with a drive device; furthermore, there is alifting device on every trolley, which devices can be spreaders, forexample, having gripping elements, for example twistlocks.

It is advantageous to dispose several trolleys behind one another on theupper and/or the lower trolley track. In this way, several trolleys canmove on the upper trolley tracks, without a load, above the trolleys onthe lower trolley tracks, and several trolleys that are carrying theirloads can move on the lower trolley tracks, next to one another and atthe same time.

For stability, trolley track connections can be disposed between the twosides of the trolley tracks, between the upper trolley tracks and thelower trolley tracks.

Furthermore, it is advantageous to structure the trolleys so that theyhave extendable power supplies. In this way, it is possible to performthe lifting and the lowering procedure of the trolley from one track tothe other, without any power supply hindering this procedure. The poweris then made available to the trolley in question by way of a storageunit, for example a battery. The lifting and lowering procedure of thetrolleys can be controlled by way of radio control. To control theprocedures of the trolleys during container loading and unloading, oneor more crane operator's cabin(s) can be disposed on the containercrane, in fixed or movable manner. It is advantageous to undertake theoperation of the trolleys automatically, whereby monitoring andregulation devices for automatic pick-up and set-down of the containersand for preventing collisions should advantageously be disposed on thecontainer crane or on the trolleys.

The multiple trolley container crane has the advantage of a simplemethod of construction, whereby several trolleys are put into use at thesame time, whereby a simultaneous switch of several trolleys on thetrolley tracks is possible, and the function of the trolleys can takeplace independently of one another, to the greatest possible extent,whereby no specific location is necessary for switching the trolleysfrom one trolley track to the other.

In the following, the invention will be explained in greater detailusing five figures and an exemplary embodiment. The figures show:

FIG. 1: Multiple trolley container crane having two trolley tracks andtwo double trolleys, unloading a ship.

FIG. 2: Multiple trolley container crane having two trolley tracks andthree triple trolleys, unloading a ship.

FIG. 3: Multiple trolley container crane having two trolley tracks andtwo quadruple trolleys, unloading a ship.

FIG. 4: Two trolleys, one above the other, on two trolley tracks, withretracted telescoping cylinder.

FIG. 5: Trolley with extended telescoping cylinder and retracted runningwheels, next to a trolley track.

FIG. 6: Two trolleys, one above the other, on two trolley tracks, withrack lifting system retracted and ready for operation, respectively.

FIG. 7: Trolley with three-step rack lifting system and retractedrunning wheels, next to the trolley track.

FIG. 8: Trolley in side view, with integrated rack lifting system.

FIG. 1 shows a container ship 1 at the pier 2, which ship is loaded withcontainers 3, whereby a container bridge 5 is performing the unloadingprocess. Six trolleys 8 are disposed on the container bridge 5, in threetrolley pairs 9, 10, 11, whereby one trolley pair 11 is disposed on theupper trolley track 6 with the lifting mechanism retracted, and standsready for being lowered onto the lower trolley track. Two trolley pairs9, 10 are located on the lower trolley track 7. The trolleys 9 havelowered their spreaders 23 onto the containers 3, and are lifting thelatter out from the cargo hold of the ship 1. After the trolleys havebeen moved in the direction towards the container transport vehicle 4,lowering of the containers 3 takes place. The trolley pair 10 is readyto be lifted onto the upper trolley track 6. For loading the ship 1, thetransport takes place in the opposite sequence.

FIG. 2 shows the container ship 1, from which containers 3 are beingremoved by three trolleys 12, which are moving on the lower trolleytrack 7, whereby additional trolleys 13 are disposed on the uppertrolley track 6, which stand ready to be moved onto the lower trolleytrack 7. The container bridge 5 spans three transport container devices4, each of which can be loaded at the same time.

FIG. 3 shows a container bridge 5 having eight trolleys 8, whereby fourtrolley pairs 14 are located in the waiting position on the uppertrolley track 6, and four trolley pairs are removing the containers 3from the ship 1, on the lower trolley track 7. Four container transportvehicles 4 stand ready for loading, under the container bridge 5.

FIG. 4 shows two trolleys 8, which are disposed on top of one another,whereby the lower trolleys 8 with its retracted running wheels 20 moveson the lower trolley track 7, and its spreader 23 carries a container 3.Another trolley 8 with extended trolley running wheels 20 is moving onthe upper trolley track 6. As a lifting system, telescoping cylinders 22are disposed next to the running wheels 20, which cylinders can be seenon both trolleys 8, in the retracted state. The spreader 23 of the uppertrolley 8 is also retracted. A current collector 19 that can be extendedto the contact line 18 is disposed between the trolleys 8 and thecontainer bridge 5, so that power can be collected if there is adifference in width between the trolley tracks 6, 7.

For stabilization, track connections 15 are disposed between the trolleytracks 6, 7.

FIG. 5 shows the current collector 19, the running wheels 20, and thespreader 23 in the retracted state, since the running trolley 8 is beinglifted from the lower track 7 to the upper track 6, by means of extendedtelescoping cylinders 22. In this connection, the telescoping cylinderssupport themselves on a support surface 29 next to the lower trolleytrack 7. After the running wheel extension position has been reached,all of the running wheels 20 extend out to the track width of the uppertrolley track 6, the telescoping cylinder 22 lowers down until therunning wheels 20 set down onto the trolley track rail 17.

FIG. 6 shows, as also shown in FIG. 4, two trolleys 8 on top of oneanother, on the trolley tracks 6 and 7. Racks 25 in the displacementcarrier 28 are disposed next to the running wheels 20, as a liftingsystem 24. The racks 25 are located in a parking position that isadvantageous for the turnover time, in the case of the upper trolley 8.In the case of the lower trolley 8 on the trolley track 7, the racks 25and the displacement carrier 28 are completely retracted.

FIG. 7 shows the integrated rack lifting system 24 in the three liftingpositions, whereby the lifting steps are carried out by way of thedually provided horizontal displacement carrier 28 with the racks 25,gear wheels 26, and the guide rollers 27. During the first liftingprocedure, the racks 25 support themselves on the support surfaces 29.After the first lift has been completed, a side displacement isperformed with the second horizontal displacement carrier 28. Thelifting procedure is continued by way of the support profile 30 andafterwards by way of the support carrier 31, until the trolley 8 hasreached the proper height for extending the running wheels 20.

FIG. 8 shows a trolley 8 in a side view, with the running wheels 20 andthe rack lifting system 24, consisting of two pairs of displacementcarriers 28 with racks 25, gear wheels 26, and guide rollers 27 that areretracted and extended, respectively, which are disposed in the headpart of the displacement carrier 28. The head part of the displacementcarrier 28 consists of two parts, whereby each part carries a rack 25and can be separately retracted and extended horizontally.

List of reference symbols used:

-   1. container ship-   2. pier-   3. container-   4. container transport vehicle-   5. container bridge-   6. upper trolley track-   7. lower trolley track-   8. trolley-   9. two trolleys—removal from ship-   10. two trolleys—trolley lift-   11. two trolleys—trolley lowering-   12. three trolleys—removal from ship-   13. three trolleys—circulation-   14. four trolleys—system-   15. track connection-   16. track combination-   17. trolley travel rails-   18. current contact line-   19. current collector-   20. trolley running wheels-   21. integrated telescoping cylinders, lifting system-   22. telescoping cylinder-   23. spreader-   24. integrated lifting system, rack-   25. rack-   26. gear wheel-   27. guide wheels-   28. horizontal displacement carrier-   29. support surface-   30. support profile-   31. support carrier

1. A multiple trolley container crane comprising: (a) at least upper andlower trolley tracks extending substantially parallel to each other; b)at least one support surface disposed below said lower trolley tracks;c) a plurality of trolleys for traveling on the trolley tracks, eachtrolley having laterally deployable and retractable running wheels, adriving device, and an integrated lifting system for supporting thetrolley on or beside the trolley tracks and enabling the trolley to passfrom the lower trolley track to the upper trolley track and vice versasuch that when at least one of said plurality of trolleys moves fromsaid lower trolley tracks to said upper trolley tracks said at least onetrolley is positioned beside said upper trolley tracks, and wherein saidat least one of said plurality of trolleys moves from said upper trolleytracks to said lower trolley tracks, said at least one trolley ispositioned beside said lower trolley tracks wherein said integratedlifting system is configured to lift a trolley above at least one ofsaid upper tracks and said lower tracks by contacting said at least onesupport surface; wherein the integrated lifting system for eachrespective trolley is selected from a group comprising verticallyoriented cylinders or telescoping cylinders and racks with gear wheelsor spokes.
 2. The multiple trolley container crane according to claim 1,wherein the trolleys are disposed, one behind the other, on at least oneof the upper trolley track and the lower trolley track.
 3. The multipletrolley container crane according to claim 2, further comprising aplurality of track connections laterally disposed between the upper andlower trolley tracks.
 4. The multiple trolley container crane accordingto claim 1, wherein a respective deployable power supply is disposed oneach trolley on contact lines along the trolley tracks.
 5. The multipletrolley container crane according to claim 1, wherein said at least onesupport surface for the integrated lifting system is disposed next tothe tracks.
 6. The multiple trolley container crane according to claim1, wherein a plurality of storage units are built on each trolley, forlifting and lowering each of said plurality of trolleys.
 7. The multipletrolley container crane according to claim 1, wherein lifting andlowering of containers is controlled via radio control from the craneoperator's cab or from another location.
 8. The multiple trolleycontainer crane according to claim 1, wherein individual trolleys or aplurality of trolleys can be moved on the trolley tracks, individuallyor in groups.
 9. The multiple trolley container crane as in claim 1,wherein said laterally deployable and retractable running wheels extendlaterally in an axial and horizontal manner.